Context : Aims : An asteroseismological study of PG 1159 - 035 , the prototype of the GW Vir variable stars , has been performed on the basis of detailed and full PG1159 evolutionary models presented by Miller Bertolami & Althaus ( 2006 ) . Methods : We carried out extensive computations of adiabatic g -mode pulsation periods on PG1159 evolutionary models with stellar masses spanning the range 0.530 to 0.741 M _ { \odot } . These models were derived from the complete evolution of progenitor stars , including the thermally pulsing AGB phase and the born-again episode . We constrained the stellar mass of PG 1159 - 035 by comparing the observed period spacing with the asymptotic period spacing and with the average of the computed period spacings . We also employed the individual observed periods reported by Costa et al . ( 2007 ) to find a representative seismological model for PG 1159 - 035 . Results : We derive a stellar mass in the range 0.56 - 0.59 M _ { \odot } from the period-spacing data alone . We also find , on the basis of a period-fit procedure , an asteroseismological model representative of PG 1159 - 035 that reproduces the observed period pattern with an average of the period differences of \overline { \delta \Pi _ { i } } = 0.64 - 1.03 s , consistent with the expected model uncertainties . The model has an effective temperature T _ { eff } = 128 000 ^ { +8 600 } _ { -2 600 } K , a stellar mass M _ { * } = 0.565 ^ { +0.025 } _ { -0.009 } M _ { \odot } , a surface gravity \log g = 7.42 ^ { +0.21 } _ { -0.12 } , a stellar luminosity and radius of \log ( L _ { * } / L _ { \odot } ) = 2.15 \pm 0.08 and \log ( R _ { * } / R _ { \odot } ) = -1.62 ^ { +0.06 } _ { -0.09 } , and a He-rich envelope thickness of M _ { env } = 0.017 M _ { \odot } . The results of the period-fit analysis carried out in this work suggest that the surface gravity of PG 1159 - 035 would be 1 \sigma larger than the spectroscopically inferred gravity . For our best-fit model of PG 1159 - 035 , all of the pulsation modes are characterized by positive rates of period changes , at odds with the measurements by Costa & Kepler ( 2007 ) . Conclusions :